Grinding-machine.



No. 833,787. PATENTED 001*. 23, 1906.

A. JOHNSTON.

GRINDINGMAGHINE. APPLICATION FILED NOV.9, 1905.

3 SHEETS-SHEET 1.

N0.-s3s.'7s7; I PATENTED 001". 23, 1906.

I A.JOHNSTON.

GRINDING MACHINE.

APPLICATION FILED NOV. 9, 1905. I I

a SHEETS-SHEET z.

PATENTED OCT. 23, 1906.

A. JOHNSTON. GRINDING MACHINE.

APPLICATION FILED NOV: 9. 1905.

SSHEETS-SHEET 3.

To all whom it may cancerm surface-of the blade.

UNITED STATES PATENT OFFICE.

i JOHNSTON, OF OTTUMWA, IOWA. GRINDING-MACHINE. No. 833,787. Specification of Letters Patent.

, lication filed November 9, 1905. Serial No. 286,568.

Be it known that I, ALLENJOHNSTQN, of

Ottumwa,- Iowa, have invented a new and useful Improvement in, Grinding-Machines, which invention is fully set forth in the following specification.

Inmy Patent No. 611,323, dated September 27, 1898, I have illustrated and describeda grinding-machine particularly ada ted to grind upon dies used for rolling or ot erwise orging the blades of table-knife blanks a surface having a twist which is the counterpart of the twist to be imparted to each I The term twist is here used to, desi nate those characteristics of the surfaces 0 the knife-blade resulting from, first, its taper' along the back or noncutting edge from the thickest part at the handle to the point of the blade; second, its cutting edgelof uniform thickness from end to end, and, third, its transverse taper from its relatively thick back or non-cutting edge to its thinner cutting. edge, this taper gradu ally decreasing from thehandle end of theblade to the oint thereof, in accordance with the longitu 'nal taper of the back edge. While the blade-surfaces having such twist are preferably. slightly convex in a trans features of the invention means the'work-holder with relation to the grinding I between the two.

verse direction," (requiring corresponding concavity in the die-surfaces,) they may also be straight. In said patent I have stated and claimed as one of the princi al novel f cr tilting surface, or vice ,versa, the important thing bein to give these parts such relative tilting and eed movements as to-impart the desired twist to the surface ground irrespective of whether these relative movements are effected' by moving only the work-holder, or by the equivalent plans of 'moving onlythe grinding-wheel, or of dividing the movements My present. invention consists of certain improvements in grinding-machines of this character and embodying the invention of said patent in which the feed and tilting movements are imparted wholly to the grinding-wheel or wheel and partly to the work-holder. These improvements may be best explained and understood by reference to the accompanyin drawings, inwhich igures 1, 2, and 3 are views of a machine in which both the feed and tiltin movements are impartedto the grinding-w eels, Fig. 1

from the left of Fig. 5.

partly to the grinding-- Patented Oct. 23, 190B.

being a vertical sectional view with parts in elevation, Fig. 2 a horizontal sectional view with arts inelevation, andFig. 3 a detail view rom the right of Figs. 1 and 2, showing only the inclined track and the end of the grinding-wheel carriage. Figs. 4, 5, and 6 are views of a machine in which the feed movement is imparted to the grinding-wheel Fig. 4 being a vertical sectional view with and the tilting movement to the work-holder,

parts in elevation, Fig. 5 a top plan view, and ig. 6 an elevation of' part 0 the machine Fig. 7' is a plan view of two dies such as used for rolling a knifeblade, said dies having a twist on their surfaces and Fig. 8 represents five sectional views taken on dotted radial lines 1 to 5, respectively, of Fig. 7. v

Referring firstto Figs. 1, 2, and 3, .10 is a tubular pedestal or pillar supporting the work-holder 11,- the latter havlng a flat top upon which rests the work (a die-block 12 in this instance) between parallel retainin flanges 13 13. A cross-bar 14, secured to flanlgtes 13by screws wor in the desired position to which it ma be accurately adjusted by bolt 16. It Wil thus be seen that in this machine the workholder, and consequently the work, are fixed. 17 is' a fan-shaped bracket or table having a split sleeve 18 embracing pedestal 10 and adaptedto be clamped at the proper eleva tion by bolts 19 19, which contract the sleeve at its split side, causing it to tightly grip the pedestal. A curved inclined track-20 1s removably fastened to the edge of bracket 17 by bolts 21, the center of curvature of the track being the axis of pedestal 10. Tracks of different'inclinatio'n may be employed, ac-

cording to the degree of twist to be imparted to the surface ground. 22 is a rin -shaped grinding-wheel, the shaft 23 of whic carries at its end a plate 24, having projecting pins 25. Shaft 23 is free to turn in a sleeve 26,

This sleeve is supporte which it is longitudinally adjustable by 15, tightly clamps the but I cannot move longitudinally therein. in a carrier 27, in

means of a hand-wheel 28 engaging a screw thread on the sleeve to move the grindingwheel to compensate for wear-in its grindingsurlace. Pins 25 enter openings in a disk 29 on the end of the drivin -shaft 30 of an electrio motor 31 and permlt the necessary adjustment of the grinding-wheel without dis connecting it from the motor. The motor is mounted upon and movable with'carr'ier 27,

its flexible conductors not being shown in the drawings. At the motor end the carrier .27 has a wheel 32, by which it is movably supported upon track 20. At its other end the carrier is supported to turn upon a horizontal axis through the conical bearingpoints of two bolts 33 34, engaging arms 35 36, respectively, of carrier 27. These bolts pass through and are supported by arms 37 and 38 of a table 39, rotat ably sleeved on pedestal 10, which table may properly be called a part of the carrier. A bridge bar 41 connects plate 29 with a sleeve 40, rotatably bearing on pedestal 10 near its base, thus adding rigidity to the support of plate 22), and consequently of the grinding-wheel end of the carrier. 42 42 are handles on table 39, by which said table, the carrier 27, and the parts mounted thereon may be rotated about the axis of the pedestal 10, the wheel 32 traveling along inclined track 20 and the table 39 turning on the pedestal as its pivot. In this rotation of the parts the wheel 32 in traveling up and down the track tilts the carrier 27 on the axis of pivots 33 and 34 from a position of minimum inclination at the lower end of the track to a position of maximum inclination at the higher end thereof. This produces a corresponding tiltingof the grinding-wheel, which in turn gradually varies the inclination of the surface ground, as shown in Figs. 7 and 8, thus producing the desired twist.

As shown in Figs. 1 and 2, the work-holder is so mounted that a line 43, Fig. 2, drawn through theaxiis on which the grindingwheel turns about the work (which is the axis of the pedestal) and at right angles to the plane of the face of the grinding-wheel (represented by dotted line 44) intersects said plane at a point outside the periphery of said wheel. In this relation of the parts the line of feed of the grinding-wheel with reference to the work will be approximately in the direction of line 45, forming an angle of less than ninety degrees with the plane of the surface of th egrinding-wheel. A slightlyconcave surface will therefore be ground upon the die-block, as shown in Fig. 8. When it is desired to grind a transversely-convex surface, the parts are so related that the line 43 intersects the plane 44 within the inner periphery of the grinding-wheel. Also by so relating the parts that line 43 intersects the grinding-surface a transversely straight surace may be ground.

In the machine of Figs. 4, 5, and 6, 50 is the tubular pedestal, in the upper end of which the stem 51 of a plate 52 is held by set-bolt 53. 54 is a work-holder held against lateral movement by side flanges 55 on plate 52. At its end nearest the grinding-wheel the work-holder is fulcrumed to tilt on a knife-edge 56, While at its other end it has an arm 56, through which a bolt 57 is adj ustably screw-threaded, said bolt bearing against a curved inclined track 53. \Vork-holder 54 has side flanges 59 52), between which the work 60 is held by a cross-bar 61. The position of the work may be adjusted by bolt 62. The grinding-wheel 63 is mounted upon a rotary carrier, which comprises sleeves (54 65, fitting about and rotatable on pedestal 5t) and rigidly connected together by a bracket-arm 66, the latter supporting bearing-bracket ()7 for the shalt (38 of the grinding-wheel. (it) is a hand-wheel operating to adjust the grindingwheel in the manner described with relation to hand-wheel 28 of Figs. 1 to 3. A pulley 7() on shaft ()8 is driven from a suitable source. of power in a manner to permit rotary movement of the carrier without interfering with the driving connections. 71 is a table also forming part of the rotary carrier and supporting track 58. By grasping handles 72 72 on this table the operative may turn the carrier and, parts mounted thereon about the axis of the pedestal. Thus while the grinding-wheel is rotating on its own axis it is also given a feed movement with relation to the work by rotation of the carrier. ltotation of the carrier also moves the inclined trac 58, upon which one end of the workholder is supported by bolt 57, thereby tilting said work-holder on the knife-edge 56 and giving the desired twist to the surface ground. In Figs. 4 to 6 the grinding-wheel and work have the same relative position as already explained with reference. to Figs. 1 to 3, resulting in the grinding of a slightly transversely concave twisted surface. By altering the construction to change the positions of the parts, as already explained, a trans versely-convex or trai1sversely-straight surface may be ground.

What I claim is 1. In a grinding-machine, the combination with a work-holder, of a grinding-wheel, a carrier on which the grinding-wheel is rotatably mounted, said carrier being movably supported to impart to the wheel a feed movement relative to the workholder, and means for relatively tilting the wheel and workholder during said feed movement to grind a twisted surface on the work.

2. In a gririding-machine, the combination with a work-holder, of a grinding-wheel, a carrier on which said wheel is rotatably .mounted, said carrier being rotatable about a fixed axis to impart to the wheel a feed movement relative to the work-holder, and means for relatively tilting the wheel and work-holder during said feed movement to grind a twisted surface on the work.

3. In a grinding-machine, the combination with a work-holder, of a grinding-wheel, a carrier on which said wheel is rotatably mounted, said carrier being rotatable about a fixed axis to impart to the wheel a feed movement relative to the work-holder, and

1o fecting relative feed movement between the 'work and wheel, one part of said carrier-supporting the grindin -w heel being pivotally connected to the ot er part to tilt relative thereto, and means for tilting said grindingwheel supporting part during said feed mmifment to grind a twisted surface on the wor 5. In a grinding-machine, the combination with a machine-pedestal, of a work-holder, a carrier journaled to turn about said edcstal as its axis or pivot, a grinding-whee rotatably mounted in bearings on said carrier, and means for relativel tilting the grindingwheel and work-ho der durmg said turning movement of the carrier to grind a twisted surface on the work.

In testimony whereof I have signed this specification in the presence of the subscribing witnesses.

ALLEN JOHNSTON.

Witnesses:

FREDK. DIMMITT, R. W. FUNK, 1

J. T. HAoKwoRTn. 

